Im trying to play LAN/Online with my friend with mods. He has a modlist he was playing with in singleplayer, worked perfectly. I could play singleplayer with the modlist aswell. however when using that exact same modlist in multiplayer, as soon as the campaign map is loaded, "player aborted" shows up on his screen (hes the host), and lost connection shows up on my screen.
we disabled every mod and then slowly enabled them to find which were causing the problem. we managed to disable the problematic mods and can play, but there was no pattern to them.

The mods causing issue are as follows;
Disable Startup Splash Screens / Intros
GCCM: Beta
Custom Siege Maps For Campaigns Compilation
Landmarks Of Legend
TEMP FIX 6.1 Expanded Roster Compilation For Decomposed Mod
Mixu's Legendary Lords (Dependency on Mixu's Legendary Lords: Asset Pack)
Rebalanced Trickster Cults & Mechanics

another player is having the same issue as me, with a different modlist https://steamhost.cn/steamcommunity_com/app/1142710/discussions/2/4038104984932241546/?l=english

We want to play with the mods that are causing issues, :(

Theres roughly 49 enabled mods, which i dont want to write down every single one to this post, so ill write the most prominent ones;
MCT
MIXER: Mixu's Unlocker
Immortal Empires Expanded
OvN Lost Factions: Albion, Fimir, Araby, Albion - Warband Submod, Citadel Of Dusk, Dread King Legions, Grudebringers, Grudgebringers Moving Camps Submod
OvN Lost World
Cataph's Southern Realms (TEB)
SCM's LCCP 15 New Factions For IEE
Legendary Characters (Dependency on Legendary Characters Assets)
Warband Upgrade Ultimate
Expanded Hero Skill Trees Compilation
Waka's Campaign Land Battles (WCLB) Map Pack